Search Results (7)

Flexible perovskite solar cells (F-PSCs) hold great potential for lightweight photovoltaic applications due to their flexibility, bending compatibility, and low manufacturing cost. However, tin oxide (SnO₂), as a common electron transport layer (ETL) used in F-PSCs, typically suffers from high-density surface defects that hinder the charge extraction efficiency and deteriorate the crystallization quality of the upper perovskite film. Additionally, the poor buried interface quality intensifies lattice extrusion and strain residue across the perovskite films, further aggravating the mechanical brittleness in devices. To address the issues, we developed a molecular bridging strategy by introducing the 2,2′-oxybis(ethylenediamine) dihydrochloride (DO) at the perovskite/SnO₂ interface. The diammonium groups of spacer ligands can achieve the bidentate anchoring on the SnO₂ and perovskite films, cooperating with the oxygen atom on the alkyl chain to passivate the charged defects at the buried interface. The tailored interface properties also endow the optimized crystallization quality of perovskite films and significantly alleviate tensile strain to strengthen the perovskite’s pliability. As a result, the F-PSCs achieved a champion efficiency of 23.50%, outperforming the value of 21.87% for the control device. Furthermore, the devices exhibited excellent mechanical robustness, maintaining 90% of the initial PCE after 6000 bending cycles at a radius of 4 mm. This work presents a reliable strategy for the synergistic optimization of the buried contact at the electron extraction interface, contributing to the further development of efficient and stable F-PSCs. Full article

Anion exchange membranes (AEM) are core components for alkaline electrochemical energy technologies, such as water electrolysis and fuel cells. They are regarded as promising alternatives for proton exchange membranes (PEM) due to the possibility of using platinum group metal (PGM)-free electrocatalysts. However, their chemical stability and conductivity are still of great concern, which is appearing to be a major challenge for developing AEM-based energy systems. Herein, we highlight an AEM with styrene-b-ethylene-b-butylene-b-styrene copolymer (SEBS) as a backbone and pyrrolidinium or piperidinium functional groups tethered on flexible ethylene oxide spacer side-chains (SEBS-Py2O6). This membrane reached 27.8 mS cm⁻¹ hydroxide ion conductivity at room temperature, which is higher compared to previously obtained piperidinium-functionalized SEBS reaching up to 10.09 mS cm⁻¹. The SEBS-Py206 combined with PGM-free electrodes in an AWE water electrolysis (AEMWE) cell achieves 520 mA cm⁻² at 2 V in 0.1 M KOH and 171 mA cm⁻² in ultra-pure water (UPW). This high performance indicates that SEBS-Py2O6 membranes are suitable for application in water electrolysis. Full article

We propose a flexible, binder-free and free-standing carbonaceous paper fabricated via electrostatic spray deposition using reduced graphene oxide/carbon nanotube (rGO/CNT) as a promising electrode material for flexible sodium-ion batteries (NIBs). The as-prepared rGO/CNT paper exhibits a three-dimensional (3D) layered structure by employing rGO as conductive frameworks to provide sodium-storage active sites and CNT as spacer to increase rGO interlayer distance and benefit the diffusion kinetics of sodium ions. Consequently, the rGO/CNT paper delivers an enhanced sodium ion storage capacity of 166.8 mAh g⁻¹ at 50 mA g⁻¹, retaining an average capacity of 101.4 mAh g⁻¹ when current density sets back 100 mA g⁻¹ after cycling at various current rates. An average capacity of 50 mAh g⁻¹ at 200 mA g⁻¹ was stabilized when cycling up to 300 cycles. The well-maintained electrochemical performance of free-standing rGO/CNT paper is due to the well-established hybrid 3D nanostructures, which demonstrates our carbon based material fabricated by a facile approach can be applied as one of the high-performance and low-cost electrode materials for applications in flexible energy storage devices. Full article

Dextran aldehyde (dexOx), resulting from the periodate oxidative cleavage of 1,2-diol moiety inside dextran, is a polymer that is very useful in many areas, including as a macromolecular carrier for drug delivery and other biomedical applications. In particular, it has been widely used for chemical engineering of enzymes, with the aim of designing better biocatalysts that possess improved catalytic properties, making them more stable and/or active for different catalytic reactions. This polymer possesses a very flexible hydrophilic structure, which becomes inert after chemical reduction; therefore, dexOx comes to be highly versatile in a biocatalyst design. This paper presents an overview of the multiple applications of dexOx in applied biocatalysis, e.g., to modulate the adsorption of biomolecules on carrier surfaces in affinity chromatography and biosensors design, to serve as a spacer arm between a ligand and the support in biomacromolecule immobilization procedures or to generate artificial microenvironments around the enzyme molecules or to stabilize multimeric enzymes by intersubunit crosslinking, among many other applications. Full article

Three new aromatic poly(imides) containing benzimidazole units in the backbone were synthesized and characterized by several spectroscopic techniques. Flexible spacer groups were incorporated into the poly(imides) structure to improve their solubility in organic solvents and their oxidative stabilization. All poly(imides) were thermally stable (T_d5% > 512 °C) and had the ability to form dense flexible films. Novel composite films were successfully prepared by loading poly(imide) with ionic liquid ([Bmim]Br) at different concentrations up to 25 wt.%. The resulting materials were characterized according to their morphology and elemental composition (SEM-EDX), water uptake capability, contact angle, and oxidative degradation resistance. Results suggested that poly(imide)/ionic liquid composites would be excellent candidates for future proton conductivity measurements. Full article

We report the preparation of a series of spacer-incorporated, tetra-amino cobalt (II) phthalocyanine (CoPc)-immobilized bacterial cellulose (BC) functional nanocomposites (CoPc@s-BC). Four kinds of flexible spacers with different lengths—diethylenetriamine (DT), triethylenetetramine (TT), tetraethylenepentamine (TP) and pentaethylenehexamine (PH)—were covalently attached onto pre-oxidized BC for the synthesis of the spacer-attached BC, and the attached spacers’ contents were carefully quantified. Using glutaraldehyde as a cross-linker, the CoPc catalyst was covalently immobilized onto the spacer-attached BC, and the immobilization steps were optimized by monitoring both the residual spacer contents and the resulting immobilized CoPc. All of the functionalization processes were characterized and confirmed by X-ray photoelectron spectroscopy (XPS). The series of spacer-incorporated, CoPc-immobilized BC nanocomposites, CoPc@s-BC, were used for the decoloration of dye wastewater. Both the adsorption capacity and adsorption rate were increased after the incorporation of spacers. When H₂O₂ was employed as an oxidant, dye molecules were catalytically oxidized with these nanocomposites. Electron paramagnetic resonance (EPR) spin-trapping results showed that the highly reactive hydroxyl radical (·OH) was involved in the catalytic oxidation process. The spacer length had a direct effect on the catalytic efficiency of CoPc@s-BC—the decoloration rate for CoPc@TP-BC was as high as 41 μmol·min⁻¹·g⁻¹, which was more than 50% higher than that without spacer. Full article

A plasma pad that can be attached to human skin was developed for aesthetic and dermatological treatment. A polyimide film was used for the dielectric layer of the flexible pad, and high-voltage and ground electrodes were placed on the film surface. Medical gauze covered the ground electrodes and was placed facing the skin to act as a spacer; thus, the plasma floated between the gauze and ground electrodes. In vitro and in vivo biocompatibility tests of the pad showed no cytotoxicity to normal cells and no irritation of mouse skin. Antibacterial activity was shown against Staphylococcus aureus and clinical isolates of methicillin-resistant S. aureus. Furthermore, skin wound healing with increased hair growth resulting from increased exogenous nitric oxide and capillary tube formation induced by the plasma pad was also confirmed in vivo. The present study suggests that this flexible and wearable plasma pad can be used for biomedical applications such as treatment of wounds and bacterial infections. Full article